_Food._--Ora W. Knight (1908) writes: "The food consists largely of beetles, grubs, flies, worms and similar insects. I have seen the birds prying frequently into the deformities on spruce and fir produced by a species of licelike insects (_Adelges_), and feel very sure that they do good work in destroying these pests, which are becoming very numerous in some sections of the State [Maine] and injuring the spruce and fir trees." W. L. McAtee (1926) praises its good looks as well as its usefulness by saying: "The beautiful Black and Yellow Warbler is a common summer resident of the higher parts of the Catskill and Adirondack regions, and breeds sparingly in local cool spots elsewhere in the State [New York]. * * * So far as known its food in our region consists entirely of insects and associated creatures, as spiders and daddy-long-legs. Almost all of its known items of insect food are sorts injurious to woodlands. It takes weevils, leaf beetles, and click beetles, leaf hoppers, plant lice, and scale insects, sawfly larvae and ants, and caterpillars and moths. Surely a record of good deeds to match the excellence of appearance of this feathered gem." F. H. King (1883) reports from Wisconsin: "Of seventeen specimens examined, three had eaten four hymenoptera, among which were two ants; one, one moth; six, seventeen caterpillars; six, fifteen diptera; six, twelve beetles; and one, two larvae. Two tipulids were represented among the diptera." Professor Aughey (1878) counted as many as 23 locusts, probably in nymphal stages, in the stomach of a magnolia warbler collected in Nebraska. And F. L. Burns (1915a) included this species with the Cape May warbler as feeding on cultivated grapes.